Ada Cambridge (21 November 1844 - 19 July 1926), later known as Ada Cross, was an English-born Australian writer. She wrote more than 25 works of fiction, three volumes of poetry and two autobiographical works. Many of her novels were serialised in Australian newspapers but never published in book form. While she was known to friends and family by her married name, Ada Cross, her newspaper readers knew her as A C. She later reverted to her maiden name, Ada Cambridge, and that is how she is known today. While Cambridge began writing in the 1870s to make money to help support her children, her formal published career spans from 1865 with Hymns on the Litany and The Two Surplices, to 1922 with an article "Nightfall" in Atlantic Monthly.